Grassley said he personally urged the president to make clear he is not wedded to a public option.

WASHINGTON (CNN) – Senator Chuck Grassley, the lead Republican in bipartisan health care negotiations, disclosed Tuesday morning that in a private meeting with President Obama earlier this month, he personally urged the president to make clear he is not wedded to a public option.

“I told the president then that he needed to make public whether or not he could sign a bill that didn't have a public option in it," Grassley said on Radio Iowa. "He didn't have to take a position against a public option, but would he sign a bill that wouldn't have a public option in it, and I thought a statement from him would be very helpful."

Grassley and the five other bipartisan negotiators met with the president on August 6, just before leaving Washington for summer recess, to discuss their efforts towards a health care bill that can pass the Senate Finance Committee in September.

On Saturday, President Obama said “the public option, whether we have it or we don’t have it, is not the entirety of health care reform.”

Then on Sunday, on CNN’s State of The Union, Health and Human Services Secretary Kathleen Sebelius said a public option is “not an essential element.”

White House spokesman Bill Burton stuck to the administration’s contention that it has not changed its position on a public option, and he expressed doubt that Grassley’s plea to the president earlier this month had any impact on the administration’s comments this past weekend.

“We’ve been in the exact same place for months,” said Burton. “I don’t know that [Grassley’s comments] would have had any bearing on Secretary Sebelius’ appearance on CNN.”

Grassley has made clear for months that a government run health insurance option is a non-starter for him, and nearly all Republicans. That’s why bipartisan Senate negotiators have been looking at non profit cooperatives instead of a public option.

But it's not just Republican opposition to a public option that poses a problem for the president. Several Democratic leadership sources say they don’t have the votes to pass a government run health care plan because of opposition, or skepticism, from conservative Senate Democrats.